Nanostructures of an amphiphilic zinc phthalocyanine polymer conjugate for photodynamic therapy of psoriasis

Potential role of herbal nanoformulations for skin disorders: a review

Aim: In the recent advanced study, the popularity of herbal nano-formulation has gained around the whole world. As we know the reason behind it is that herbal products have comparatively lesser side effects than other synthetic products. Significance: These natural plant extracts have wide medicinal importance as they increase the overall bioavailability of products toward tissues. Key findings: This review provides the use of different herbal nano-formulations, their safety considerations, and the challenges being faced. It also highlights the various Clinical Trials and Patents that are published for skin disorders. Conclusion: The present review describes how the rise of herbal products has made wider interest in transdermal formulations and improve the overall productivity by preventing various skin disorders.

Pathology and Treatment of Psoriasis Using Nanoformulations

Psoriasis (PSO) is an inflammatory skin condition that causes a variety of diseases and significantly decreases the life characteristics of patients, and substantially diminishes patients' quality of life. PSO usually impairs the skin and is linked to various disorders. Inflammation pathology does not only damage psoriatic skin; it shows how PSO impinges other body parts. Many variables interact with one another and can impact the etiology of psoriasis directly or indirectly. PSO has an effect on approximately 2% of the world's population, and significant progress has been made in comprehending and treating the alternative PSO by novel drug delivery systems. Topical, systemic, biological, biomaterials, and phototherapy are some of the useful therapies for PSO. Nonetheless, topical treatments remain the gold standard for treating moderate PSO. The applicability of several nanocarrier systems, such as lipid nanoparticles, metallic nanoparticles, and certain phytocompounds, has been briefly explored. The present review focuses mainly on traditional therapeutic strategies as well as on breakthroughs in nanoformulations and drug delivery methods for several anti-psoriatic drugs.

Albumin microbubbles conjugated with zinc and aluminum phthalocyanine dyes for enhanced photodynamic activity

Gas-liquid interfaces are reaching a particular interest in biomedicine. Microbubbles, ultrasound contrast agents of clinical routine, gained increasing attention as theranostic platforms due to the preserved acoustic response, drug conjugation capabilities, and applicability in biological barrier opening. A combination of microbubbles and photodynamic therapy agents can enhance the photodynamic effect, yet the evaluation of agent conjugation on microbubble stabilization and photodynamic effect is needed. Hence, two commercially available phthalocyanine photosensitizers - Holosens® (ZnPc) and Photosens® (AlPc) - were coupled with bovine serum albumin before microbubble synthesis. We demonstrated an albumin: phthalocyanine ratio of 1:1 and covalent attachment for ZnPc, a ratio of 1:3 with electrostatic binding for AlPc. Submicron-sized microbubbles (air- and SF6- filled) had a diameter of 0.8 µm. Albumin-phthalocyanine conjugates increased the microbubble concentration and shelf-life stability compared to plain ones. We hypothesized that phthalocyanine fluorescence lifetime values decreased after conjugation with microbubbles due to narrow distance between conjugates in the shell. Agents based on AlPc demonstrated higher photodynamic activity than agents based on ZnPc, and microbubbles preserved acoustic stability in human blood plasma. The biodistribution of AlPc-conjugated microbubbles was evaluated. We conclude that our microbubble platforms demonstrate greater photodynamic activity and prolonged stability for further applications in photodynamic therapy.

Polymeric Nanosystems Applied for Metal-Based Drugs and Photosensitizers Delivery: The State of the Art and Recent Advancements

Nanotechnology-based approaches for targeting the delivery and controlled release of metal-based therapeutic agents have revealed significant potential as tools for enhancing the therapeutic effect of metal-based agents and minimizing their systemic toxicities. In this context, a series of polymer-based nanosized systems designed to physically load or covalently conjugate metal-based therapeutic agents have been remarkably improving their bioavailability and anticancer efficacy. Initially, the polymeric nanocarriers were applied for platinum-based chemotherapeutic agents resulting in some nanoformulations currently in clinical tests and even in medical applications. At present, these nanoassemblies have been slowly expanding for nonplatinum-containing metal-based chemotherapeutic agents. Interestingly, for metal-based photosensitizers (PS) applied in photodynamic therapy (PDT), especially for cancer treatment, strategies employing polymeric nanocarriers have been investigated for almost 30 years. In this review, we address the polymeric nanocarrier-assisted metal-based therapeutics agent delivery systems with a specific focus on non-platinum systems; we explore some biological and physicochemical aspects of the polymer–metallodrug assembly. Finally, we summarize some recent advances in polymeric nanosystems coupled with metal-based compounds that present potential for successful clinical applications as chemotherapeutic or photosensitizing agents. We hope this review can provide a fertile ground for the innovative design of polymeric nanosystems for targeting the delivery and controlled release of metal-containing therapeutic agents.

Exploring the potential of nanocarriers in antipsoriatic therapeutics

Psoriasis is an autoimmune disease characterized by erythematous, scaly patches on the skin. It can be effectively managed with topical therapies since they deliver drugs to target sites of disease efficiently and can minimize systemic side-effects while ensuring high patient compliance. However, conventional topical formulations are ineffective in treating psoriasis due to their poor percutaneous penetration and inability to reach deeper layers of the skin. Thus, it is important to explore new approaches for managing psoriasis safely and effectively while also maintaining patient compliance without compromising safety. Over the last few decades, a variety of nanocarriers have been extensively investigated as a new approach to delivering drugs to the skin that are effective against psoriasis. These nanocarriers are notable for their therapeutic effectiveness, increased localization of medication in the skin, and reduced side-effects. The purpose of this review is to explore the recent advances in polymer-based, lipid-based, metallic, and microneedle-based novel nanoformulations of antipsoriatic drugs. There have been detailed discussions about several nanocarrier systems including nanoemulsions, liposomes, nanostructured lipid carriers, ethosomes, solid lipid nanoparticles, micelles, gold nanoparticles, silver nanoparticles, and microneedles. In a nutshell, nanoformulations are considered a promising avenue for psoriasis treatment since they offer better penetration, targeted delivery, and enhanced safety and efficacy.

Transdermal Delivery of Therapeutic Compounds With Nanotechnological Approaches in Psoriasis

Psoriasis is a chronic, immune-mediated skin disorder involving hyperproliferation of the keratinocytes in the epidermis. As complex as its pathophysiology, the optimal treatment for psoriasis remains unsatisfactorily addressed. Though systemic administration of biological agents has made an impressive stride in moderate-to-severe psoriasis, a considerable portion of psoriatic conditions were left unresolved, mainly due to adverse effects from systemic drug administration or insufficient drug delivery across a highly packed stratum corneum via topical therapies. Along with the advances in nanotechnologies, the incorporation of nanomaterials as topical drug carriers opens an obvious prospect for the development of antipsoriatic topicals. Hence, this review aims to distinguish the benefits and weaknesses of individual nanostructures when applied as topical antipsoriatics in preclinical psoriatic models. In view of specific features of each nanostructure, we propose that a proper combination of distinctive nanomaterials according to the physicochemical properties of loaded drugs and clinical features of psoriatic patients is becoming a promising option that potentially drives the translation of nanomaterials from bench to bedside with improved transdermal drug delivery and consequently therapeutic effects.

Photoactivated cell-killing amino-based flavylium compounds

Photodynamic therapy (PDT) is a well-established therapeutic for the treatment of different diseases. The growing interest of this technique required the development of new photosensitizers with better photo-features. This work reports the study of the potential of five nature-inspired amino-based flavylium compounds with different structural features as photosensitizers towards topical PDT. In terms of dark cytotoxicity the five pigments were tested towards confluent skin cells in both fibroblasts and keratinocytes. In the range of concentrations tested (6.3–100 μM), keratinocytes were more prone to growth inhibition and the IC₅₀ values for 5OH4′NMe₂, 7NEt₂st4′NMe₂ and 7NEt₂4′NH₂ were determined to be 47.3 ± 0.3 μM; 91.0 ± 0.8 μM and 29.8 ± 0.8 μM, respectively. 7NEt₂4′NMe₂, 7NEt₂st4′NMe₂ and 7NEt₂4′NH₂ showed significant fluorescence quantum yields (from 3.40 to 20.20%) and production of singlet oxygen (¹O₂). These latter chromophores presented IC₅₀ values of growth inhibition of keratinocytes between 0.9 and 1.5 µM, after 10 min of photoactivation with white light. This cellular damage in keratinocyte cells upon white light activation was accompanied with the production of reactive oxygen species (ROS). It was also found that the compounds can induce damage by either type I (ROS production) or type II (singlet oxygen) PDT mechanism, although a higher cell survival was observed in the presence of ¹O₂ quenchers. Overall, a structure–activity relationship could be established, ranking the most important functional groups for the photoactivation efficiency as follows: C7-diethylamino > C4′-dimethylamino > C2-styryl.

Topical Application of Vitamin D3-Loaded Hybrid Nanosystem to Offset Imiquimod-Induced Psoriasis

Lipid-polymer hybrid nanoparticles display several benefits over either lipid and/or polymer based systems with respect to enhanced drug loading, good colloidal stability, sustained release profile, and high cellular uptake. The present work rivets on development and evaluation of vitamin D₃-loaded monolithic lipid-polymer hybrid nanoparticles (VD3/LPHNPs) for their in vivo anti-psoriatic efficacy. These LPHNPs were prepared using a hot homogenization method and exhibited spherical morphology with a lower particle size (123.1 nm) with narrow PDI (0.234) and efficient encapsulation (76.80%). Further, these LPHNPs demonstrated a sustained release profile of VD3 for up to 3 days following a Korsemeyer-Peppas release model. Further, VD3/LPHNPs were formulated into a topical gel containing 0.005% w/w of VD3. Rheological data suggested that the product exhibited non-newtonian flow properties with characteristic shear-thinning and variable thixotropy features that are desirable for topical formulation. The successful formation of gel structure and its long-term stability were confirmed from the oscillatory studies such as amplitude and frequency sweep tests. In vivo efficacy assessment in imiquimod-induced psoriatic mouse model demonstrated enhanced anti-psoriatic activity of VD3 with improved PASI score when delivered as LPHNPs gel as compared to the free VD3 gel that were further supported by histopathology and immunohistochemistry.

Application of photodynamic therapy in immune-related diseases

Photodynamic therapy (PDT) is a therapeutic modality that utilizes photodamage caused by photosensitizers and oxygen after exposure to a specific wavelength of light. Owing to its low toxicity, high selectivity, and minimally invasive properties, PDT has been widely applied to treat various malignant tumors, premalignant lesions, and infectious diseases. Moreover, there is growing evidence of its immunomodulatory effects and potential for the treatment of immune-related diseases. This review mainly focuses on the effect of PDT on immunity and its application in immune-related diseases.

Reconstituted high density lipoprotein (rHDL), a versatile drug delivery nanoplatform for tumor targeted therapy

rHDL is a synthesized drug delivery nanoplatform exhibiting excellent biocompatibility, which possesses most of the advantages of HDL. rHDL shows almost no toxicity and can be degraded to non-toxic substances in vivo. The severe limitation of the application of various antitumor agents is mainly due to their low bioavailability, high toxicity, poor stability, etc. Favorably, antitumor drug-loaded rHDL nanoparticles (NPs), which are known as an important drug delivery system (DDS), help to change the situation a lot. This DDS shows an outstanding active-targeting ability towards tumor cells and improves the therapeutic effect during antitumor treatment while overcoming the shortcomings mentioned above. In the following text, we will mainly focus on the various applications of rHDL in tumor targeted therapy by describing the properties, preparation, receptor active-targeting ability and antitumor effects of antineoplastic drug-loaded rHDL NPs.

Polymers in topical delivery of anti-psoriatic medications and other topical agents in overcoming the barriers of conventional treatment strategies

In recent decades, topical treatments to dermal disorders have shown ineffectiveness in delivering the medication at a particular location without a suitable drug carrier. Psoriasis treatment is hindered because of the ineffective delivery and efficacy of conventional pharmaceutical treatment. In conventional medication formulation approach, it is difficult to breach the transdermal layer of a skin membrane for topical drugs, i.e. cyclosporine, methotrexate. This problem is further complicated by extreme disease-associated conditions such as hyperkeratosis and irritation. Intending to assure better drug delivery carriers, this review emphasizes the therapeutic efficacy of polymers and their potential to deliver the drug into the deeper layer of the skin membrane. The polymers are essential in structural and physiochemical perspectives as it works as a carrier for the medication. A vast variety of delivery carriers is available nowadays but their applicability in such dermal cases like psoriasis is still lacking due to less knowledge on an appropriate polymer. The current investigation of suitable polymer would assist in brushing our expertise to optimize the advantages of a wide spectrum of polymers to fulfill the topical targeting of psoriasis.

Biophysical Characterization and Anticancer Activities of Photosensitive Phytoanthraquinones Represented by Hypericin and Its Model Compounds

Photosensitive compounds found in herbs have been reported in recent years as having a variety of interesting medicinal and biological activities. In this review, we focus on photosensitizers such as hypericin and its model compounds emodin, quinizarin, and danthron, which have antiviral, antifungal, antineoplastic, and antitumor effects. They can be utilized as potential agents in photodynamic therapy, especially in photodynamic therapy (PDT) for cancer. We aimed to give a comprehensive summary of the physical and chemical properties of these interesting molecules, emphasizing their mechanism of action in relation to their different interactions with biomacromolecules, specifically with DNA.

Topical photodynamic therapy combined with ablative "light needles" against basal cell carcinoma

Basal cell carcinoma (BCC), a non-melanoma cancer with high morbidity in the elders, is a type of limited skin cancer with a projected appearance. Traditional treatments such as oral or injection administration are likely to result in serious side effects. Here, we developed a strategy that combined photodynamic therapy (PDT) with ablative light "needles" (carbon-dioxide laser) for the treatment of BCC, involving β-Tetra-(4-carboxyl-phenoxy)-zinc phthalocyanine (ZnPC₄) cubic phases with high drug loading, easy preparation, long local retention, good spreading ability and little toxicity. A model of nude mice with BCC was established for the study of pharmacodynamics. The light needles of low energy (53 mJ/cm²) used here could promote transdermal absorption of ZnPC₄ cubic phases while those of high energy (238 mJ/cm²) alone could completely kill tumor cells with no recurrence. However, ZnPC₄ cubic phases alone could not completely inhibit tumor growth, for it was distributed mainly at the topical administration site in the absence of any adjuvant technology. Therefore, the combination of photodynamics and light needles offered a good solution. Especially, the combined use of light needles with high energy and ZnPC₄ cubic phases can treat BCC efficiently with no recurrence. This approach is expected to be a novel and promising medication against BCC.

Treatment of Psoriasis: A Comprehensive Review of Entire Therapies

Background:

Psoriasis is an autoimmune disease that ingeminates itself with the repeated proliferation of keratinocytes. It globally strikes a 2-5 % population on an average. Management of psoriasis remains a daunting task with various challenges influencing treatment, such as patient conformity and adherence to therapy, delicate patient profiles, psychological aspects, and skin as a barrier to topical delivery. The first part reviewed pathophysiology, triggering factors, and clinical classification. The second part reviewed all the therapies, such as topical, oral, biological, parenteral therapy, phototherapy, and the phyto-pharmaceuticals.

Methods:

The research data related to the existing and upcoming therapies for psoriasis treatment, several nanocarriers, existing marketed formulations, and detailed description of phytopharmaceuticals with their mechanism.

Results:

Topical therapy is the mainstay treatment option with limited adverse effects. Biological therapy has reformed conventional psoriasis treatment by being more efficacious and has increased patient acceptance due to decreased adverse events. Nanoformulations present an edge over conventional therapy due to improved anti-psoriatic effect and decreased side effects. Phyto-pharmaceuticals act as a complementary and alternative therapy for diminishing psoriasis symptoms.

Conclusion:

A rationalized cost-effective patient compliant therapy is required for effective management and complete cure of psoriasis.

Porphyrin Derivative Nanoformulations for Therapy and Antiparasitic Agents

Porphyrins and analogous macrocycles exhibit interesting photochemical, catalytic, and luminescence properties demonstrating high potential in the treatment of several diseases. Among them can be highlighted the possibility of application in photodynamic therapy and antimicrobial/antiparasitic PDT, for example, of malaria parasite. However, the low efficiency generally associated with their low solubility in water and bioavailability have precluded biomedical applications. Nanotechnology can provide efficient strategies to enhance bioavailability and incorporate targeted delivery properties to conventional pharmaceuticals, enhancing the effectiveness and reducing the toxicity, thus improving the adhesion to the treatment. In this way, those limitations can be overcome by using two main strategies: (1) Incorporation of hydrophilic substituents into the macrocycle ring while controlling the interaction with biological systems and (2) by including them in nanocarriers and delivery nanosystems. This review will focus on antiparasitic drugs based on porphyrin derivatives developed according to these two strategies, considering their vast and increasing applications befitting the multiple roles of these compounds in nature.

Photodynamic Therapy of Psoriasis Using Photosensitizers of Vegetable Origin

Psoriasis is an immune-mediated, chronic and recurrent inflammatory skin disease, prevalent worldwide, and represents an important burden in life quality of patients. The most common clinical variant is termed as psoriasis vulgaris or plaque psoriasis, which with an individualized and carefully monitored therapy can decrease the patients' morbidity and improving their life quality. The aim is to achieve disease control, minimize the adverse drug effects, and tailor the treatment to individual patient factors. Photodynamic therapy (PDT) is based on local or systemic administration of a non-toxic photosensitizer followed by irradiation with a particular wavelength to generate reactive oxygen species (ROS), mainly highly cytotoxic singlet oxygen (1O2). The generation of these species results in the attack to substrates involved in biological cycles causing necrosis and apoptosis of affected tissues. Photosensitizers are found in natural products and also obtained by partial syntheses from abundant natural starting compounds. They can be isolated at low cost and in large amounts from plants or algae. Therefore, this manuscript reviews the use of molecules from vegetal sources as photosensitizer agents for the PDT of psoriasis. Psoriasis pathogenesis, management and treatment were reviewed. PDT principles, fundamentals and utilization for the treatment of psoriasis were also discussed. Photosensitizers for PDT of psoriasis are also reviewed focusing on those from vegetal sources. Despite the PDT is utilized for the treatment of psoriasis, very little amount of photosensitizers from plant sources are utilized, such as chlorophyll derivatives and hypericin; however, other natural photosensitizers such as curcumin, could also be investigated. They could constitute a very important, safe and cheap alternative for the successful photodynamic treatment of psoriasis.

Assessing Amphiphilic ABAB Zn(II) Phthalocyanines with Enhanced Photosensitization Abilities in In Vitro Photodynamic Therapy Studies Against Cancer

We have previously demonstrated that singlet oxygen photosensitization abilities of Zn(II) phthalocyanines (Zn(II)Pcs) are enhanced through α-functionalization with bulky fluorinated substituents (i.e., bis(trifluoromethyl)phenyl units) at facing positions of ABAB Zn(II)Pcs, where A and B refer to differently functionalized isoindoles. In this work, we have prepared the Zn(II)Pc ABAB 1 endowed with hydrophilic triethylene glycol monomethyl ether (i.e., at the A isoindoles) to provide solubility in aqueous media, together with its A₃B and A₄ counterparts, and compared their ability to behave as photosensitizers for photodynamic therapy. All photophysical data, aggregation studies and preliminary in vitro biological assays in cell cultures of SCC-13 (squamous cell carcinoma) and HeLa (cervical cancer cells), have proved ABAB 1 as the best photosensitizer of the series.

Topical 5-aminolevulinic acid photodynamic therapy for intra anal-rectal warts

Background: Condylomata acuminata (CA) are a common sexually transmitted disease. The recurrence rate of condyloma acuminatum using traditional treatments is higher than that of applying photodynamic therapy, and a variety of adverse reactions after treatment. At the same time, different parts of condyloma acuminatum after treatment recurrence rate is also different, especially for intra anal-rectal warts.Objective: To evaluate whether using photodynamic therapy (PDT) can effectively reduce recurrence of condylomata acuminata for intra anal-rectal warts.Methods: After the confirmation of the diagnosis of intra anal-rectal warts, the patients were treated with PDT with 5-aminolevulinic acid hydrochloride (ALA). PDT was performed with irradiation of 18-36 J/cm² at an irradiance of 20-40 mW/cm² with light-emitting diode (LED) light energy, wavelength 635 nm. We used a special PDT light equipment for intra anal-rectal area warts. PDT was repeated once every week for 4 weeks.Results: After PDT, the complete clearance rate was 76.1% (35 of 46 patients). At the end of the 12 weeks followed, recurrence occurred in five cases. We recorded pain in all 46 patients and the average visual analog scale (VAS) pain score was 6.96 ± 1.41 points.Conclusion: The treatment with PDT is effective in reducing the high rate of recurrence for intra anal-rectal warts. Pain is still a great challenge for the therapy.

Porphyrinoid-based photosensitizers for diagnostic and therapeutic applications: An update

Porphyrin-based molecules are actively studied as dual function theranostics: fluorescence-based imaging for diagnostics and fluorescence-guided therapeutic treatment of cancers. The intrinsic fluorescent and photodynamic properties of the bimodal molecules allows for these theranostic approaches. Several porphyrinoids bearing both hydrophilic and/or hydrophobic units at their periphery have been developed for the aforementioned applications, but better tumor selectivity and high efficacy to destroy tumor cells is always a key setback for their use. Another issue related to their effective clinical use is that, most of these chromophores form aggregates under physiological conditions. Nanomaterials that are known to possess incredible properties that cannot be achieved from their bulk systems can serve as carriers for these chromophores. Porphyrinoids, when conjugated with nanomaterials, can be enabled to perform as multifunctional nanomedicine devices. The integrated properties of these porphyrinoid-nanomaterial conjugated systems make them useful for selective drug delivery, theranostic capabilities, and multimodal bioimaging. This review highlights the use of porphyrins, chlorins, bacteriochlorins, phthalocyanines and naphthalocyanines as well as their multifunctional nanodevices in various biomedical theranostic platforms.

Chlorin, Phthalocyanine, and Porphyrin Types Derivatives in Phototreatment of Cutaneous Manifestations: A Review

Recent scientific research has shown the use of chlorin, phthalocyanines, and porphyrins derivatives as photosensitizers in photodynamic therapy in the treatment of various pathologies, including some of the major skin diseases. Thus, the main goal of this critical review is to catalog the papers that used these photosensitizers in the treatment of acne vulgaris, psoriasis, papillomavirus infections, cutaneous leishmaniasis, and skin rejuvenation, and to explore the photodynamic therapy mechanisms against these conditions alongside their clinical benefits.

Synergistic Effects of Photo-Irradiation and Curcumin-Chitosan/Alginate Nanoparticles on Tumor Necrosis Factor-Alpha-Induced Psoriasis-Like Proliferation of Keratinocytes

Psoriasis is a chronic inflammatory skin disease characterized by hyperproliferation of the epidermal cells and is clinically presented as thick, bright red to pink plaques with a silvery scale. Photodynamic therapy (PDT) using visible light has become of increasing interest in the treatment of inflammatory skin diseases. In this study, we demonstrate that a combination of curcumin-loaded chitosan/alginate nanoparticles (Cur-CS/Alg NPs) and blue light emitting diodes (LED) light irradiation effectively suppressed the hyperproliferation of tumor necrosis factor-alpha (TNF-α)-induced cultured human kerlatinocyte (HaCaT) cells. The Cur-CS/Alg NPs were fabricated by emulsification of curcumin in aqueous sodium alginate solution and ionotropic gelation with calcium chloride and chitosan using an optimized formulation derived from a Box-Behnken design. The fabricated Cur-CS/Alg NPs were characterized for their particle size, zeta potential, encapsulation efficiency, and loading capacity. The surrogate 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay, to measure the relative number of viable cells, showed that the CS/Alg NPs were nontoxic to normal HaCaT cells, while 0.05 µg/mL and 0.1 µg/mL of free curcumin and Cur-CS/Alg NPs inhibited the hyperproliferation of HaCaT cells induced by TNF-α. However, the Cur-CS/Alg NPs demonstrated a stronger effect than the free curcumin, especially when combined with blue light irradiation (10 J/cm²) from an LED-based illumination device. Therefore, the Cur-CS/Alg NPs with blue LED light could be potentially developed into an effective PDT system for the treatment of psoriasis.

Synthesis and Encapsulation of a New Zinc Phthalocyanine Photosensitizer into Polymeric Nanoparticles to Enhance Cell Uptake and Phototoxicity

Efforts to enhance the utility of photodynamic therapy as a non-invasive method for treating certain cancers have often involved the design of dye sensitizers with increased singlet oxygen efficiency. More recently, however, sensitizers with greater selectivity for tumor cells than surrounding tissue have been targeted. The present study provides an approach to the modification of the known photosensitizer zinc phthalocyanine (ZnPc), to enhance its solubility and delivery to cancer cells. Targeting a photosensitizer to the site of action improves the efficacy of the sensitizer in photodynamic therapy. In this work we used PLGA-b-PEG to encapsulate a new zinc phthalocyanine derivative, 2(3), 9(10), 16(17), 23(24)-tetrakis-(4’-methyl-benzyloxy) phthalocyanine zinc(II) (ZnPcBCH3), to enhance uptake into A549 cells, a human lung cancer cell line. ZnPcBCH3 exhibited the same photochemical properties as the parent compound ZnPc but gave increased solubility in organic solvents, which allowed for efficient encapsulation. In addition, the encapsulated dye showed a near 500-fold increase in phototoxicity for A549 cancer cells compared to free dye.

The synthesis and investigation of photochemical, photophysical and biological properties of new lutetium, indium, and zinc phthalocyanines substituted with PEGME-2000 blocks

Zinc(II) (5), indium(III) (6), and lutetium(III) (7) phthalocyanines (Pcs) peripherally substituted with poly (ethylene glycol) (PEG) monomethyl ether 2000 (PEGME-2000) blocks were synthesized via Sonogashira coupling reaction with high yields and their photophysical, photochemical and photobiological properties were investigated. We elucidated the interactions of these compounds with calf thymus DNA and bovine serum albumin (BSA), and determined K_(DNA) and K_(BSA) binding constants at degrees of 10⁵ and 10⁶, respectively. Singlet oxygen quantum yields were found (Ф_∆ = 0.44, 0.54, and 0.68 for 5, 6, and 7, respectively). Thermodynamic parameters, as well as thermal denaturation profile of double-stranded CT-DNA were examined to determine the type of binding mode. According to our experimental data, we report that PEGME-2000 favors the formation of binary complex between DNA, and phthalocyanine complexes. Therein, thermodynamic data suggest that this binding mode is indeed spontaneous under reported conditions, and rather non-specific. Additionally, Pcs 5, 6, and 7 substituted with PEGME-2000 blocks showed antimicrobial activity against Gram-positive and Gram-negative bacteria, as well as fungi (yeast), and Pc 5 had the highest antimicrobial activity among them, as revealed by disc diffusion assay results. In short, our results suggest that these compounds could be used for photodynamic therapy, they have both antibacterial and antifungal activity, and the binding ability of new phthalocyanines 5, 6, and 7 with BSA paves the way for their utilization as drug vehicle in blood plasma.

Understanding the prospective of nano-formulations towards the treatment of psoriasis

Psoriasis is a consistently recurring, inflammatory, autoimmune disorder of the skin, affecting about 2-5% of the world population. Abundant therapeutic agents are accessible for the treatment of psoriasis. Nevertheless, none of them are entirely secure and effective to treat the disease without compromising patient compliance. Furthermore, already existing drugs are supposed to restrain the ailment and alleviate the sign and symptoms with no complete cure. However, they focus on restraining the disease and alleviating the symptoms without providing an absolute cure. Therefore there remains a vital challenge, to explore a new drug moiety or delivery system which could safely and effectively manage psoriasis without compromising patient compliance. Furthermore, conventional formulations offer reduced benefit/risk ratio of anti-psoriatic drugs, which limits the use of existing conventional formulations. Novel formulations based on nanocarriers are a promising prospect to overcome the limitation of conventional formulations by offering a reduction in dose, dosing frequency, dose-dependent, side effects with enhanced efficacy. Presently nano-formulations have gained widespread application for effective and safe treatment of psoriasis. The present review primarily focuses on conventional therapeutic strategy and recent advances in lipid-based, polymer-based and metallic nano-formulations of a variety of anti-psoriatic drugs. The practicability of various nanocarrier systems including liposomes, nanostructured lipid carriers, ethosomes, solid lipid nanoparticles, nanocapsules, micelles, dendrimers, gold nanoparticles and silver nanoparticles have been discussed in detail. The review also traces related patents to exemplify the role of various nanoparticles in psoriasis treatment. In a nutshell, nano-formulations remain established as a promising modality for treating psoriasis treatment as they propose better penetration, targeted delivery, enhanced safety, and efficacy.

Doxorubicin-Loaded Photosensitizer-Core pH-Responsive Copolymer Nanocarriers for Combining Photodynamic Therapy and Chemotherapy

Photodynamic therapy (PDT) is an emerging method for the treatment of cancer. Combination of PDT and chemotherapy is a hot topic though the two therapies could not simultaneously exert their perfect effect in vivo. Here we report a doxorubicin-loaded photosensitizer-core pH-responsive copolymer nanocarrier with high tumor targeting and anticancer effects due to integration of PDT with chemotherapy. The pH-responsive photosensitizer-core four-armed star-shaped copolymer, [methoxy-poly(ethylene glycol)-poly(2-(N,N-diethylamino)ethyl methacrylate)-poly(ε-caprolactone)]₄-zinc β-tetra-(4-carboxyl benzyloxyl)phthalocyanine (PDCZP), was prepared, which was a molecular spherical nanocarrier in aqueous media. The carriers changed from small at high pH to large at low pH (51, 105, and 342 nm at pH 7.4, 6.5, and 5.0, respectively) and the zeta potential gradually increased (7.15, 16.2, and 26.1 mV at the above pH, respectively). PDCZP had a longer emission wavelength (max. 677 nm) than the parent photosensitizer, favoring light penetration through biological tissues. The singlet oxygen (¹O₂) quantum yield of PDCZP was 0.41. Doxorubicin (DOX) showed rapid release from PDCZP in the acidic media. More importantly, the drug-loaded nanocarriers showed the better in vitro and in vivo anticancer effects under lighting on MCF-7, SW480 cells and HepG2 cells and the murine hepatocellular carcinoma H₂₂ models than the other groups. PDCZP showed a high tumor targeting effect based on the enhanced permeation and retention effect and its small size. The photosensitizer-core nanocarrier is a promising photodynamic nanocarrier for integrating other therapies.

Biomimetic HDL nanoparticle mediated tumor targeted delivery of indocyanine green for enhanced photodynamic therapy

Photodynamic therapy has emerged as a promising strategy for cancer treatment. To ensure the efficient delivery of a photosensitizer to tumor for anticancer effect, a safe and tumor-specific delivery system is highly desirable. Herein, we introduce a novel biomimetic nanoparticle named rHDL/ICG (rHDL/I), by loading amphiphilic near-infrared (NIR) fluorescent dye indocyanine green (ICG) into reconstituted high density lipoproteins (rHDL). In this system, rHDL can mediate photoprotection effect and receptor-guided tumor-targeting transportation of cargos into cells. Upon NIR irradiation, ICG can generate fluorescent imaging signals for diagnosis and monitoring therapeutic activity, and produce singlet oxygen to trigger photodynamic therapy (PDT). Our studies demonstrated that rHDL/I exhibited excellent size and fluorescence stability, light-triggered controlled release feature, and neglectable hemolytic activity. It also showed equivalent NIR response compared to free ICG under laser irradiation. Importantly, the fluorescent signal of ICG loaded in rHDL/I could be visualized subcellularly in vitro and exhibited metabolic distribution in vivo, presenting superior tumor targeting and internalization. This NIR-triggered image-guided nanoparticle produced outstanding therapeutic outcomes against cancer cells, demonstrating great potential of biomimetic delivery vehicles in future clinical practice.

Topical PDT in the Treatment of Benign Skin Diseases: Principles and New Applications

Photodynamic therapy (PDT) uses a photosensitizer, light energy, and molecular oxygen to cause cell damage. Cells exposed to the photosensitizer are susceptible to destruction upon light absorption because excitation of the photosensitizing agents leads to the production of reactive oxygen species and, subsequently, direct cytotoxicity. Using the intrinsic cellular heme biosynthetic pathway, topical PDT selectively targets abnormal cells, while preserving normal surrounding tissues. This selective cytotoxic effect is the basis for the use of PDT in antitumor treatment. Clinically, PDT is a widely used therapeutic regimen for oncologic skin conditions such as actinic keratosis, squamous cell carcinoma in situ, and basal cell carcinoma. PDT has been shown, under certain circumstances, to stimulate the immune system and produce antibacterial, and/or regenerative effects while protecting cell viability. Thus, it may be useful for treating benign skin conditions. An increasing number of studies support the idea that PDT may be effective for treating acne vulgaris and several other inflammatory/infective skin diseases, including psoriasis, rosacea, viral warts, and aging-related changes. This review provides an overview of the clinical investigations of PDT and discusses each of the essential aspects of the sequence: its mechanism of action, common photosensitizers, light sources, and clinical applications in dermatology. Of the numerous clinical trials of PDT in dermatology, this review focuses on those studies that have reported remarkable therapeutic benefits following topical PDT for benign skin conditions such as acne vulgaris, viral warts, and photorejuvenation without causing severe side effects.

Developments in PDT Sensitizers for Increased Selectivity and Singlet Oxygen Production

Photodynamic therapy (PDT) is a minimally-invasive procedure that has been clinically approved for treating certain types of cancers. This procedure takes advantage of the cytotoxic activity of singlet oxygen (¹O₂) and other reactive oxygen species (ROS) produced by visible and NIR light irradiation of dye sensitizers following their accumulation in malignant cells. The main two concerns associated with certain clinically-used PDT sensitizers that have been influencing research in this arena are low selectivity toward malignant cells and low levels of ¹O₂ production in aqueous media. Solving the selectivity issue would compensate for photosensitizer concerns such as dark toxicity and aggregation in aqueous media. One main approach to enhancing dye selectivity involves taking advantage of key methods used in pharmaceutical drug delivery. This approach lies at the heart of the recent developments in PDT research and is a point of emphasis in the present review. Of particular interest has been the development of polymeric micelles as nanoparticles for delivering hydrophobic (lipophilic) and amphiphilic photosensitizers to the target cells. This review also covers methods employed to increase ¹O₂ production efficiency, including the design of two-photon absorbing sensitizers and triplet forming cyclometalated Ir(III) complexes.